Apparatus for producing return bend fittings



March 18, 1941 P. L. IRVING EI'AL APPARATUS FOR PRODUCINGRETURN' BENDFITTINGS Filed Jan. 2, 1940 3 Sheets-Sheet 1 March 18, 1941. p L. lRVlNGETAL 2,235,072

APPARATUS FOR PRODUCING RETURN BEND FITTINGS Filed Jan. 2, 1949 3Sheets-Sheet 2 k1 IILUQII Z'bns & L Irving Kari/1.1 THAm/Zel March 18,1941. p IRWNG ETAL 2,235,072

APPARATUS FOR PRODUCING RETURN BEND FITTINGS Filed Jan. 2, 1940 :5Sheets-Sheet s M 341 ZZ z/ [4 e a! f 2 g g 5?. I i 1 K? C I Z 5f Z 3d 3X3 Patented Mar. 18, 1941 UNITED STATES PATENT OFFICE APPARATUS FORPRODUCING RETURN BEND FITTINGS Application January 2, 1940, Serial No.311,976

Claims.

Our invention relates to improvements in the art of bending of metaltubing and has more particular relation to the formation of pipefittings such as return bends, elbows, and the like, from straighttubing. Our invention is especially adapted to the formation of soldertype fittings from copper tubing, and to the successive forming andsevering of such fittings from long lengths of tubing.

Among the objects of ourinvention is the reduction in the cost ofproduction of fittings, especially return bends, from lengths of tubing,and we accomplish this by facilitating the removal and discharge of thefittings from the forming mechanism by a method employing positive,quick acting power mechanism, instead of the slow and uncertain manualmethods commonly employed in these operations.

Another object is the elimination of the danger of physical injury tothe operator occasioned by the manual removal of the formed fittingsfrom the forming mechanism.

Other objects of our invention will appear hereinafter.

Referring to the accompanying drawings,

Fig. 1 is a view in elevation of an ejecting mechanism in operatingrelation to the tube bending mechanism, by which the return bend,fittings are formed and severed from the tube lengths;

Fig. 2 is an end elevation of the mechanism shown in Fig. 1, theejecting mechanism being shown as swung out of alignment with theforming mechanism to permit the insertion of tube lengths from which thereturn bends are formed;

Fig. 3 is a top plan view of the turret on which the bending form andtube clamping mechanism are mounted, these parts being shown in positioncorresponding to the beginning of the forming operation;

Fig. 4 is a similar view of the parts shown in Fig. 3, but in positioncorresponding to the completion of the forming operation;

Fig. 5 is an enlarged detail partly in section on a line correspondingto the line 5--5 of Fig. 2, showing a tube length on a mandril andclamped against the bending form ready to be given a U-bend;

Fig. 6 is an enlarged detail plan of the ejector device shown in Fig. 1in engaging position with respect to the forming mechanism;

Fig. 7 is a view in elevation of the ejector device shown in Fig. 6;

Fig. 8 is a detail view of one of the fingers carried by the ejectordevice for engaging the formed or bent tube after it has been severedfrom the tube length;

Figs. 9, 10, and 11 are detail views in plan of the ejector device andforming mechanism in difierent relative positions to illustrate theseveral steps in the method of ejecting the formed articles, Fig. 9showing the ejector approaching and beginning engagement with thesevered return bend, Fig. 10 showing the ejector having completedengagement with the ends of the return bend, and Fig. 11 showing theejector device withdrawing the formed return bend from the formingmechanism to release it for discharge into a suitable receptacle.

U-shaped or return bend pipe fittings of the solder type, especiallythose made of copper, are formed from long lengths of tubing by machineswhich bend the end portion of the tubing into a U-form and then cut theformed article from the length. The tubing is then fed forward and 20the operations are repeated until the length of tube is used up,whereupon another long length of tubing is inserted into the machine andthe operations repeated as before.

The machine which we have illustrated in the drawings is of the typewhich has a bending form or block A conformed to the shape of the bendto be made and to which the tube B is clamped and around which it isdrawn when the bending form is rotated. In the present instance, this 30machine is arranged to simultaneously form three return bends from threeseparate lengths of pipe or tubing, but it is understood that inprinciple the operations are the same whether a single or a plurality ofarticles are formed, and that the number of articles simultaneouslyformed is in practice governed by the size of the fitting to beproduced.

The bending form A is carried upon a turret l which is rotatablehorizontally upon a vertical axis and which is mounted upon a base orstandard 2 as part of the frame of the whole machine. The turret and thebending form are rotated by suitable power mechanism such as hydraulicmeans, through the gear 3 and rack 4, Figs. 1 and 2. The bending form A,as shown more clearly in Fig. 5, has a forming portion ill and aclamping portion H, the forming portion being rounded or curved to forma U-shaped bend in the tube. The faces of the forming and clampingportions in and H of the bending form have channels or grooves 12 forthe tubing, these channels being conformed to the circumference of thetube and of a depth substantially equal to the radius of the tube, sothat the groove embraces substantially one-half of the circumference ofthe tube. The bending form also has a transverse vertical slot M whichseparates the clamping and forming portions and into which a saw orcutter l5 enters to cut the tube and sever the U-shaped portion C fromthe length.

The long lengths of tubing B from which the return bends C are formedand severed, are carried on long mandrils 29 extending the length of themachine frame. The tubes are slipped onto these mandrils from theforming end of the machine. At the rear end of the machine, the tubesand mandrils are connected to suitable hydraulic mechanism which aftereach forming operation advances them forward into position for the nextforming operation. The forward portions of the tubes are thus positionedalongside the bending form in the grooves thereof. The extreme endportions 2| of the tubes overlie the clamping portion ll of the bendingform and are gripped between said clamping portion H and a clamping jawmember 22 which is correspondingly grooved and which is slidably mountedon an arm 23 extending outwardly from and movable with the turret I.Suitable hydraulic actuating mechanism operates the clamping jaw towardsand from the tube to grip and release as the operations require.

Each of the mandrils has at its end a ball member 24 on a short stem 25hinged at 26 to the mandril (Fig. 5). These ball members serve as diesto maintain the roundness of the tubing and prevent buckling as thetubing is bent around the bending form. The mandrils are advanced withthe tubing so that the ball dies occupy the positions within the clampedend portions 2| of the tubes where they are held until the clamps close.They are then retracted sufiiciently to clear the slot l4 and heldstationary while the tubing is drawn over them in the process of bendingthe tubing around the bending form.

The cutting of the tubes is accomplished by means of a circular saw !5illustrated diagrammatically in Figs. 1, 2 and 9, which is carried bysuitable operating mechanism and is adapted to be brought down into theslot H1 in a plane transversely of the longitudinal axis of the tubes.The saw cuts across the body of the tubes and also the end portions 2|which become waste ends. The saw cut thus determines the length of thelegs of the formed return bends C. The saw is of sufiicient thickness sothat the cuts through the portions 2! and the tube bodies are ofappreciable width to provide space for the entry of the ejectormechanism.

The extreme power necessary to bend the tubing leaves the return bends Ctightly wedged in the grooves of the bending form. Heretofore thepractice has been for the operator to manually pry the return bendsloose from the bending form and remove them, so that the next formingoperation could be carried out. The manual removal of the U-bends fromthe machine not only is costly because slow and uncertain, especiallywhere several return bends were simultaneously formed as in the presentmachine, but it actually endangers the operators hands by subjecting himto too close proximity to the mechanism, particularly the cutting saw.

In accordance with our invention, we provide a method of ejecting theformed return bends which can be carried out by suitable power-actuatedejecting mechanism under the control of the operator, wherebyimmediately upon the completion of the forming and cutting operationsthe equally to both of these leg ends to forcibly with- 1 draw anddislodge the return bends from the bending form and carry themsufliciently clear of the machine to discharge them into a suitablereceptacle. The mechanism for carrying out this method comprises anejector device which is arranged to be reciprocated towards and from thebending form, and which is adapted upon its forward stroke to engage thereturn bends, and upon its return or retraction stroke to dislodge thereturn bends from the bending form and pull them away from the end ofthe machine sufiiciently so that they will drop into a suitablereceptacle.

The ejector comprises a tube engaging device D carried on the end of thepiston rod 28 of the power-actuating mechanism E by which it is movedtowards and from the forming machine. The ejector device consists of ahead or cross member 29 which has two parallelly disposed plates 30spaced apart and hinged at 3| to swing outwardly. The hinges are formedto provide stops 32 which hold the outer ends of the plates spaced aparta slightly greater distance than the width of the return bend. Theplates are yieldingly held against the stop by springs 33 which areattached to pins 34 on the plates and on the head. At their outer endsthe plates carry fingers 35 which are directed inwardly toward eachother and which are of proper thickness to freely enter the saw outwhich severed the return bends C from the tube. The inner ends of thesefingers are spaced apart a lesser distance than the width of the returnbend so that as the ejector device approaches the return bends (Fig. 9)the edges of these fingers ride on the return bends and spread theplates 30 apart until the fingers reach the saw cut at the ends of thereturn bend legs. They then'ride off the ends of the return bend legsand under the influence of the springs 33 are forced into the saw cutsin position to engage said ends (Fig. 10). Upon retraction of theejector device (Fig. 11), the fingers apply a positive force equally toboth legs of the return bends in a direction outwardly and away from thebending form. The fingers have curved notches 35 in their edges,conforming to the curvature of the circumference of the tubing. Thefingers are adjustably secured by the screws 36 to the edges of theplates 30 and may be readily removed and replaced by other fingersadapted to the number and size of the return bends.

The piston rod 28 extends into the end of a cylinder 31 and is securedto a piston 33 actuated by fiuid pressure such as compressed air in thecylinder. The piston is reciprocated in the cylinder and thereby impartsthe forward and retraction or withdrawal strokes to the ejector device.

The cylinder and its heads 39 are held in assembled relation by means ofthe rods d0 extending between the heads. The heads 39 are ex tendedbelow the cylinder to form feet which are secured at the upper end of aframe or standard 4| which supports the power-actuated ejector mechanismat the proper level with respect to the bending form. In order toprevent rotation of the ejector device, the member 29 is connected by anarm 52 to a guide rod 53 which slides in bearings 54 in the extensionsof the cylinder heads. The operating position of the ejector mechanismis substantially in line with the bending form and the long lengths oftubing in the forming machine. The frame or standard M, however, ispivoted at 42in a base member 43 so that the whole ejector unit can beswung laterally out of alignment with the bending machine sufiicientlyto enable new lengths of tubing to be inserted into the forming machine.The standard 4| has a stop arm 44 which serves as a stop to limit theswing of the frame and support it in that position while the operator isreplenishing tube lengths in the machine. On the front side the framehas an outstanding similar stop 45 which holds the frame and the ejectorunit in its operating position in alignment with the forming machine.This latter stop arm has an inclined cam 46 which cooperates with alocking device to hold the unit in alignment. This look ing deviceconsists of an upright shaft 49 hav ing at its lower end a link 48 inwhich a pin 4! is carried and which engages the cam 46 when the operatorrotates the shaft 49 (Figs. 1 and 2). A convenient handle i! is providedfor the operator at the upper end of the shaft 49. At the upper portionof the standard 4| a handle bar 44 is provided which the operator mayconveniently grasp to bodily swing the standard and ejector unit toeither of its positions.

Any suitable means may be provided by which the operator is enabled tocontrol the fluid pressure in the power-actuating cylinder 31.

At one end of the cylinder stripper plates 55 are mounted and located atthe end of the retraction stroke of the ejector device. These strippersare in the form of cam-shaped plates (Fig. 11) which engage the pins 34and act to spread the hinged plates 30 of the ejector device apartsufficiently so as to definitely release any return bends that may becarried outwardly by the ejector device, thus freeing the ejectordevicefor the next operation,

The operation of the mechanism is as follows: Assuming that the formingmechanism has been charged with long lengths of tubing and that theejector mechanism has been swung back into operating alignment with thetube forming mechanism. The bending form A to which the end portion ofthe tubing B is clamped, is rotated by the turret I to bend the tubingaround the form A and thereby form U-shaped bends or portions C. Uponthe completion of this forming operation, the circular saw or cutter I5is brought into the slot l4 and cuts transversely through the tubing tosever the U-portion from the tube length and to sever the waste-endportion 2!. The saw is then retracted to its upper position. The formedand severed U-bends are now ready to be removed from the bending form sothat the bending form can be reversely rotated in position to clamp theend portions of the tube lengths and repeat the next forming operation.The operator supplies fluid (air pressure) to the cylinder E, whichprojects the ejector mechanism D toward the bending form A. As theejector mechanism approaches the bending form, the fingers 35 ride onthe U-bends, spreading the plates 30 apart against the tension of thesprings 33; and as the fingers pass the severed ends of the U-bends,they enter the saw slot in the tubing and under the influence of thesprings 33 engage the ends of the U-bend legs. The operator thenreverses the fluid pressure in the cylinder 31 and reverses the movementof the ejector mechanism. This retracts or withdraws the ejectormechanism from the bending form A and the fingers pull the formedU-bends from the bending form and carry them clear of the formingmechanism. The bending form A is then returned to its original positionand the operation of forming the U- portions at the ends of the tubingand the ejection thereof from the machine is again repeated. Theoperation of the ejector mechanism is positive and is sufficiently rapidso that there is no delay between the successive forming operations ofthe tube-forming mechanism.

One embodiment of our invention has been described and illustrated inconnection with the formation of that type of pipe fitting generallyknown as return bend or U-shaped fittings. It is obvious, however, thatthe construction, operation, and arrangement of parts may be changed toadapt them to the production of other forms of fittings from tubingwithout departing from the spirit of the invention; and it is to beunderstood that our invention includes such changes in construction,operation, and arrangement of parts as fairly fall within the scope ofthe appended claims.

We claim:

1. In a machine of the class described, the combination of a pipebending mechanism having a forming block and power means forsuccessively bending the end portion of a pipe length around said blockto form a U-shaped bend, means for cutting said U-shaped bendtransversely to sever it from the pipe length, and power-actuatedejector mechanism for ejecting said U-shaped bend from said formingblock and including fingers adapted to enter the cut and engage the endsof said U-bend, and fluid operated means for actuating said fingers todislodge the U-bend from the forming block.

2. In a machine for producing return bend fittings successively from along length of tubing, the combination of a. bending fonm, poweractuatedmeans for successively bending the end portion of the tubing around saidbending form to form a U-shaped bend in the tube, means for successivelycutting the u shaped bend from the tube length and forming a spacebetween the severed ends, an ejector having fingers for entering saidspace and engaging the ends of said U-shaped bends, and power means formoving said ejector away from the bending form to dislodge .the bendsfrom said bending form.

3. In a power-actuated machin for bending tubing, the combination of aforming member, means for bending tubing around said forming member toform U-shaped'bends, a cutting device operative in a plane transverse tothe axis of the tubing to sever the U-shaped bend from the tubing, anejector movable toward and from the bending form and including a memberhaving yielding arms arranged upon the forward stroke of said ejector tobe positioned adjacent the legs of the U-shaped bend, fingers carried bysaid arms adapted to be moved by said yielding arms into engagementswith the severed ends of said U-shaped bend and pull the bend away fromthe bending form upon the return stroke of said ejector, and power meansfor actuating said ejector.

l. The combination of a powenactuated tube bending machine forsuccessively forming and cutting U-shaped bends from a long length oftubing having a forming die around which the tube is bent, and apower-actuated ejector device positioned in operating relation to theforming die and adapted to be moved toward the forming die intoengagement with the U- shaped bends and away from the said forming dieto remove the formed bends therefrom, said ejector device including apair of spaced-apart arms and means at the end of said arms adapted toride on said formed bends and engage the severed ends thereof during theforward movement of the ejector, and to apply sufficient force todislodge the formed bends from the di during the return movement of saidejector, and means supporting said ejector device for movement into andout of operating position to permit the insertion into the formingmachine of long lengths of tubing 5. The combination of a power-aotuatedtube bending machine for successively forming and cutting U-shaped bendsfrom a long length of tubing having a forming die around which the tubeis bent, and a power-actuated ejector device positioned in operatingrelation to the forming die and adapted to be moved toward the formingdie into engagement with the U-shaped bends and away from the saidforming die to remove the formed bends therefrom, said ejector deviceincluding a pair of spaced-apant arms and means at the end of said armsadapted to ride on said formed bends and engage the severed ends thereofduring the forward movement of the ejector, and to apply sufiicientforce to dislodge the formed bends from th die during the returnmovement of said ejector, and means operable during the return movementof said ejector for spreading the arms to release the formed bendswithdrawn from the die.

PHILIP L. IRVING.

ERHART P, KUNKEL.

